WATER RESOURCES AUTHORITY WATER RESOURCES SITUATION REPORT AUGUST 2018 July 2017 to June 2018 Contents List of Figures .............................................................................................................................. iii List of Tables .................................................................................................................................. v Abbreviations and Acronyms .................................................................................................... vi Excecutive Summary .................................................................................................................. vii 1 INTRODUCTION ......................................................................................................................... 1 1.1 Overview ............................................................................................................................... 2 1.2 This Report ............................................................................................................................ 3 1.3 Data Availability ................................................................................................................... 4 2 CLIMATE........................................................................................................................................ 6 2.1 Description of Monitoring Network .................................................................................... 6 2.2 Improvements to Network .................................................................................................. 7 2.3 Analysis of Rainfall, Evaporation & Climate ..................................................................... 8 2.4 Comments on Special Events ............................................................................................. 16 2.5 Special Studies ..................................................................................................................... 16 3 SURFACE WATER RESOURCES ................................................................................................ 17 3.1 Description of Monitoring Network ................................................................................ 17 3.2 Improvements to Network Infrastructure ....................................................................... 18 3.2.1 Lake Victoria North Basin Area ................................................................................ 18 3.2.2 Lake Victoria South Basin Area ................................................................................. 19 3.2.3 Rift Valley Basin Area ................................................................................................ 19 3.2.4 Tana Basin Area ......................................................................................................... 19 3.2.5 Tana Basin Area ......................................................................................................... 20 3.3 Improvements to Data Quality ......................................................................................... 21 3.4 Assessment of Surface Water Resources ........................................................................... 21 3.4.3 Tana Basin Area .......................................................................................................... 23 3.4.4 Ewaso Ng’iro North Basin Area ............................................................................... 23 3.5 Comments on Special Events ............................................................................................. 25 3.5.1 Flooding ...................................................................................................................... 25 3.5.2 Violation of the Reserve ............................................................................................ 29 3.6 Special Studies ..................................................................................................................... 29 3.6.1 Flood Mapping for Lower Tana basin ..................................................................... 30 3.6.2 Erosion Risk Mapping for Nzoia Watershed .......................................................... 32 4 SURFACE WATER QUALITY ..................................................................................................... 38 4.1 Description of Monitoring Network ................................................................................ 38 4.1.1 Non point pollution monitoring ..................................................................................... 39 i 4.2 Instrumentation ................................................................................................................... 40 4.3 Improvements to Network Infrastructure ....................................................................... 41 4.4 Improvements to Data Quality ......................................................................................... 41 4.5 Assessment of Surface Water Quality ............................................................................... 41 4.5.1 Non-Point Source Pollution ...................................................................................... 41 4.6 Comments on Special Events ............................................................................................. 48 4.7 Special Studies ..................................................................................................................... 49 5 GROUNDWATER RESOURCES ................................................................................................ 50 5.1 Description of Monitoring Network ................................................................................ 50 5.2 Instrumentation expected at each type of station .......................................................... 51 5.3 Improvements to Network Infrastructure ....................................................................... 52 5.4 Assessment of Groundwater ............................................................................................... 52 5.4.1 Water Level ................................................................................................................. 53 5.5 Comments on Special Events ............................................................................................. 61 5.5.1 Kikuyu Groundwater Conservation Area ................................................................ 61 5.5.2 Lamu Groundwater Conservation Area .................................................................. 62 5.5.3 Borehole Database ..................................................................................................... 63 5.6 Special Studies ..................................................................................................................... 64 5.7 Challenges and Opportunities in collection of groundwater data ............................... 64 6 WATER USE ................................................................................................................................ 66 6.1 Permits .................................................................................................................................. 66 6.1.1 Type of permits issued ............................................................................................... 66 7 EMERGING ISSUES ..................................................................................................................... 70 ANNEXES .......................................................................................................................................... 71 Annex 1: Special studies and capital projects done in 2017/18 financial year ..................... 71 Annex 2A: Map of aquifers within ENNCA ............................................................................ 73 Annex 2B: Map of aquifers within TCA .................................................................................. 73 Annex 2C: Map of aquifers within RVCA ............................................................................... 74 Annex 2D: Map of aquifers within LVNCA ............................................................................ 75 Annex 2E: Map of Monitoring boreholes within LVSCA ...................................................... 76 Annex 3A: Ground Water Monitoring Stations in aquifers within ENNCA ....................... 78 Annex 3B: Ground Water Monitoring Stations in aquifers within RVCA ........................... 79 Annex 3C: Ground Water Monitoring Stations in aquifers within LVNCA ........................ 80 Annex 4: Final PDB Transactions Report ................................................................................ 80 Annex 5: List of Meters .............................................................................................................. 81 ii List of Figures Figure 1.1: Datasets received in the FY 2017/18 .............................................................................. 5 Figure 2.1: Rainfall monitoring network .......................................................................................... 7 Figure 2.2: Comparatve Rainfall for Ndaragwa Rainfall Station for 2 years ............................ 10 Figure 2.30: Embu RO Office Met Station 4 Yearly Trends ........................................................ 13 Figure 2.41: Meru DWO Rainfall station- Yearly Trends ............................................................. 14 Figure 2.52: